JPH0727814Y2 - Vacuum pump drive motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vacuum pump drive motor for driving a rotary vacuum pump.

[Prior art]

Conventionally, as a vacuum pump driving motor of this type, there has been one having a structure as shown in FIGS. 2 to 4.

The vacuum pump drive motor shown in FIG.
The drive shaft 11 and the main shaft 21 of the motor 20 are connected by a shaft joint 30. The motor 20 has a structure in which a stator core 23 is fixed to a frame 22, and a main shaft 21 into which a rotor core 24 is fitted and fixed is rotatably supported by bearings 25 and 26 at both ends thereof.

The vacuum pump drive motor shown in FIG.
The motor 20 and the motor 20 are enclosed in a single frame 31. In the figure, the parts denoted by the same reference numerals as those in FIG. 2 indicate the same or corresponding parts (hereinafter, the same applies to other drawings).

The vacuum pump driving motor shown in FIG. 4 has a structure in which the vacuum pump 10 and the motor 20 are hermetically sealed in a single frame 31 as in FIG. 3, but a stator consisting of a stator core 23 is used as a stator can 19. The enamel copper wire and core of the stator coil are prevented from being corroded by the corrosive gas handled in the vacuum pump 10 and the insulation deterioration is prevented.

[Problems to be solved by the invention]

However, the vacuum pump drive motors shown in FIGS. 2 to 4 all have the following problems.

The motor for driving the vacuum pump of FIG. 2 requires the shaft seal device 12 to maintain the vacuum of the vacuum pump 10. Therefore, leakage of the shaft seal of the rotating part is unavoidable, and the entire device is large to maintain the vacuum. However, there is a problem in that the reliability of the device becomes lower as it becomes more common. Further, in order to transmit the rotational force of the motor 20 to the vacuum pump 10, a shaft coupling 30 that connects the drive shaft 11 of the vacuum pump 10 and the main shaft 21 of the motor 20 is required, which causes an increase in the size and cost of the device. There was also a problem.

In the structure shown in FIG. 3 in which the vacuum pump 10 and the motor 20 are hermetically sealed in a single frame 31, the shaft sealing device 12 is not required, but the shaft coupling 30 is required, so the equipment is large and the cost is increased. At the same time, the magnetic material (silicon steel plate) of the stator core 23 and the rotor core 24, which is important as a constituent material of the motor 20, the enamel copper wire (magnet wire) of the stator,
There is a problem in that aluminum or copper, which is a conductive material of the rotor secondary conductor, causes corrosion or insulation deterioration depending on the gas handled in the vacuum pump 10 and shortens the motor life.

In the sealing structure shown in FIG. 4, since the stator having the stator core 23 and the like is sealed with the stator can 27, the stator core 23
And the magnetic material of the rotor core 24, the problem of shortening the motor life due to corrosion and insulation degradation of the enamel copper wire can be avoided, but the need for the shaft coupling 30 makes the equipment larger,
There was a problem such as cost increase.

Further, in any of the above vacuum pump drive motors, the heat generated by the loss of the motor is radiated directly from the outer periphery of the frame, so that heat convection of air is caused around the motor, and particularly clean air such as in a clean room is allowed to flow in a certain direction. Therefore, for the system that maintains the cleanliness of the room, there is a drawback that the air flow is disturbed and the function of the clean room is impaired.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to eliminate the above-mentioned problems, and to provide a vacuum pump drive motor that is compact and lightweight, and that does not cause bearing loss or heat convection around the motor.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention has a stator core fixed to a motor frame, a motor main shaft into which a motor rotor is fitted and fixed is connected to a drive shaft of a rotary vacuum pump, and drives the rotary vacuum pump. In the vacuum pump drive motor, the frame of the vacuum pump and the motor frame are integrally formed, the vacuum pump drive shaft and the motor main shaft are integrally formed, and the bearing of the motor main shaft is shared with the bearing of the vacuum pump drive shaft. The motor part does not have a bearing, the outer peripheral part of the frame in contact with the stator core of the motor is surrounded by an outer wall, and the space surrounded by the outer peripheral part and the outer wall has a structure in which the refrigerant is passed through the cooling chamber. The motor rotor and the stator are sealed by a rotary rotor can and a stator can, respectively.

[Action]

By configuring the vacuum pump driving motor as described above, the bearing of the motor main shaft is located outside the motor main body and cantilevered, so that the motor portion can be made compact and lightweight. Further, since the cooling chamber is provided on the outer peripheral portion of the frame of the motor, the heat generated by the loss of the motor is radiated directly from the outer periphery of the frame, and the problem of causing thermal convection of air around the motor is solved. Further, the frame of the vacuum pump and the motor frame are integrally structured, and the vacuum pump drive shaft and the motor main shaft are integrally structured,
Further, the bearing of the motor main shaft is also used as the bearing of the vacuum pump drive shaft, and the structure in which the motor portion has no bearing reduces the size of the entire device and reduces the bearing loss because the motor has no bearing. Disappear. Further, by adopting a structure in which the motor rotor and the stator are hermetically sealed by the rotor can and the stator can, respectively, even when the vacuum pump handles corrosive gas, the magnetic material and the enamel of the stator core and the rotor core are used. The motor life will not be shortened due to corrosion or deterioration of insulation of copper or aluminum, which is a conductive material of the secondary conductor.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the structure of a vacuum pump device using a vacuum pump driving motor according to the present invention. As shown, the vacuum pump 10 and the motor 20 are housed in a single frame 32. The stator core 23 of the motor 20 is fixed inside the frame 32. An outer wall 33 is provided on the outer periphery of the frame 32 with a predetermined gap, and the gap formed by the frame 32 and the outer wall 33 serves as a cooling chamber 34. An inlet 36 and an outlet 35 for introducing a cooling medium such as water, oil or air into the cooling chamber 34.
Are formed. Drive shaft 11 of vacuum pump 10 and motor 20
The main shaft is integrally formed, the bearing 12 of the drive shaft 11 of the vacuum pump 10 and the main shaft bearing of the motor 20 are shared, and no bearing is provided on the motor side, that is, a cantilever structure. Incidentally, 13 is a bearing of the vacuum pump 10, 27 is a stator coil of the motor 20, and 28 is a secondary conductor. Also, the stator core 23
And the stator coil including the stator coil 27 and the like.
The rotor is provided with a rotor core 24, a secondary conductor 28, and the like, and is sealed with a rotor can 24a and a rotor side plate 24b.

In the vacuum pump device having the above structure, the motor 20 generates a rotating magnetic field by the stator coil 27 and the stator core 23, and the rotating magnetic field is induced to the secondary conductor 28 and the rotor core 24 by an electromagnetic induction action to generate a rotating force. It is a so-called induction motor that is generated. The rotational force of the motor 20 is transmitted to the vacuum pump 10 by the main shaft that is integrated with the drive shaft 11 to rotate the vacuum pump 10. In this case, since there is no bearing on the motor side, the bearing loss of the motor 20 is eliminated.

The loss that occurs in the stator of the motor 20
There are copper loss (Joule heat loss) due to the current flowing in 27 and iron loss due to the magnetic flux flowing in the stator core 23. The loss generated in the rotor is the copper loss due to the current flowing in the secondary conductor 28 (Joule heat loss). Loss) and iron loss due to the magnetic flux flowing through the rotor core 24. Most of these losses become heat and are transmitted mainly through the frame 32 to the outer periphery thereof. So frame 32
By passing a cooling medium such as water or oil through the cooling chamber 34 provided on the outer periphery of the motor 20, heat generation of the motor 20 is removed, and the temperature rise of the outer peripheral surface of the motor 20 is suppressed. Therefore, for example, the motor 20 is used in a clean room. However, it does not become a hot spot that disturbs the gentle flow of clean air in the room. Further, by providing the outer wall 33 on the outer circumference of the frame 32, there is also a soundproof effect of reducing the magnetic sound and the like generated from the motor 20 by the outer wall 33.

Further, as shown in FIG. 3 to FIG. 5, the structure is not provided with the shaft coupling 30 and the bearings 25 and 26, and the motor 20
Since there is no bearing inside, the vacuum pump device can be downsized.

Further, the stator including the stator core 23 and the stator coil 27 of the motor 20 is sealed with the stator can 23a, and the rotor including the rotor core 24, the secondary conductor 28 and the like is rotated by the rotor can 24.
A vacuum pump can be created by sealing with a and rotor side plate 24b.
Even if the corrosive gas (including toxic gas) handled on the 10 side enters the motor 20, the stator core 23, the stator coil 27,
There is no risk of corrosion of the rotor core 24, the secondary conductor 28, etc., and insulation deterioration.

The stator can 23a and the rotor can 24a are composed of a thin cylinder made of a non-magnetic material (for example, corrosion-resistant non-magnetic steel such as stainless steel, Inconel, Hastelloy, Carpenter, and titanium). From the rotor side to the rotor side. To facilitate the transmission of the magnetic flux, reduce the gap between the stator side and the rotor type, that is, the air gap, and reduce the magnetic resistance, thereby reducing the magnetic loss and improving the efficiency.

Since the entire vacuum pump device has no seal mechanism in the rotating part, that is, it has a safe sealing structure with only a static seal mechanism,
The corrosive gas or highly toxic gas handled by the vacuum pump 10 leaks to the outside, and the safety is extremely high without causing any corrosion, fire, other disasters, or adverse effects on biological systems.

[Effect of device]

As described above, according to the present invention, the following excellent effects can be obtained.

Since the cooling chamber is provided on the outer periphery of the motor frame, the heat generated by the loss of the motor is directly radiated from the outer periphery of the frame, causing heat convection of air around the motor.For example, this vacuum pump drive motor can be installed in the clean room. When used, the outer peripheral portion of the motor does not become a so-called hot spot that disturbs the flow of clean air.

Further, since the bearing of the motor main shaft is located outside the main body of the motor and is supported by a cantilever, the motor unit can be made compact and lightweight.

Further, the frame of the vacuum pump and the motor frame are integrally formed, the vacuum pump drive shaft and the motor main shaft are integrally formed, and the bearing of the motor main shaft is also used as the bearing of the vacuum pump drive shaft. By adopting a structure that does not have a bearing, the entire device becomes smaller and lighter, and the bearing loss of the motor is eliminated because the motor does not have a bearing.

Further, the motor rotor and the stator are sealed by the rotor can and the stator can, respectively, so that even if the vacuum pump handles corrosive gas, the magnetic material and the enamel of the stator core and the rotor core are used. The motor life will not be shortened due to corrosion of the copper wire or the conductive material of the secondary conductor and deterioration of insulation.

[Brief description of drawings]

FIG. 1 is a diagram showing a structure of a vacuum pump device using a vacuum pump driving motor according to the present invention, and FIGS. 2 to 4 are diagrams showing a structure of a conventional vacuum pump device. In the figure, 10 ... vacuum pump, 11 ... driving shaft, 12 ... bearing,
20 …… motor, 21 …… spindle, 23 …… stator core, 24 ……
Rotor core, 25 …… Bearing, 27 …… Stator coil, 28 ……
Secondary conductor, 32 …… frame, 33 …… outer wall, 35 …… exit,
36 ... Entrance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-63-1772 (JP, A) real-opening Sho-60-73892 (JP, U) real-opening Sho-55-141271 (JP, U) real-opening Sho-59- 101047 (JP, U) Actual public 50-17042 (JP, Y1)

Claims (1)

[Scope of utility model registration request] 1. A stator core is fixed to a motor frame,
A motor for driving a rotary vacuum pump, in which a motor main shaft having a motor rotor fitted and fixed is connected to a drive shaft of the rotary vacuum pump, wherein the frame of the vacuum pump and the motor frame are integrated. In addition, the vacuum pump drive shaft and the motor main shaft are integrally structured, the bearing of the motor main shaft is also used as the bearing of the vacuum pump drive shaft, and the motor portion has no bearing. The outer peripheral portion of the frame in contact with the core is surrounded by an outer wall, and the space surrounded by the outer peripheral portion and the outer wall has a structure in which a coolant is passed through the cooling chamber. Further, the motor rotor and the stator are respectively a rotor can and a stator can. A vacuum pump drive motor characterized by being sealed with.